<template>
  <div>
    <button @click="sub">-</button>
    <span >{{value}}</span>
    <button @click="add">+</button>
  </div>
</template>

<script>
export default {
  name: 'NumberBox',
  props:['value'],
  methods:{
    add(){
      this.$emit('input',this.value+ 1)
    },
  sub(){
    this.$emit('input', this.value-1)
  }
  },
}
</script>

<style lang="less" scoped>
span {
  display: inline-block;
  margin: 0 5px;
}
</style>